Personal cleansing compositions are available in wide ranging product formats e.g. from soap bars, liquid soap, body-wash compositions and self-foaming compositions to shampoos. Sometimes such cleansing compositions are also included in cleansing wipes.
Personal cleansing compositions are formulated for specific purpose, such as antibacterial effect and exfoliation to mild and gentle cleansing.
Usually the pH of mild cleansing compositions is close to or less than 7. Even if the pH of such compositions is alkaline, it is usually below 8. The reason is that generally strongly alkaline cleansers such as conventional bars of soap and soap-containing liquid cleaners are considered to be harsh. On the other hand, conventional SLES-CAPB based cleaning compositions having pH of about 5 to 7 are generally considered gentle and mild and therefore these surfactants form the base of many such compositions.
There is a growing demand for mild liquid cleansing formulations which additionally have an antibacterial effect. Antibacterial cleansers are preferred because they kill germs and mild personal cleansers are preferred as their use leads to minimal skin irritation and dryness. However, the combination of mild cleansing formulations and strong antibacterial effect is difficult to achieve.
Thus, for example, while soaps provide antibacterial effects, they are not mild to the skin. When very mild non-soap surfactants are used, antibacterial effect is greatly compromised due to the requirement to formulate them around neutral pH for better performance.
The balancing act between providing mildness and effective antibacterial effectiveness is recognized for example in International Publication WO 92/18100 A1. In this publication, improved clinical mildness is said to be provided through the use of a water soluble cationic polymer. Cationic polymer is apparently used instead of additional ethoxylated surfactant because the percent of ethoxylated mildness surfactant must be minimized in order not to affect antibacterial effectiveness.
It can be readily seen that there is a technical problem to provide effective antibacterial action in the presence of very mild surfactants.
WO9532705 A1 (Unilever) discloses mild antibacterial cleansers but their pH is in the acidic range.
WO2011138179A1 (Unilever) discloses a mild cleansing composition having specific mild surfactant system with good foam and phase stability. The surfactant system includes alkanoyl glycinates and amphoacetate surfactants. The composition also includes emollients for good foaming and mildness. The pH of the compositions is less than 8.
WO2012/022614A1 discloses mild isotropic liquid compositions having specific surfactant system which includes glycinates, amphoteric surfactants and alkyl sulfates and the pH of the resultant compositions is in the narrow range of 6.5 to 7.5. The associative acrylate polymer provides inter-alia, mildness.
Antibacterial personal cleansing compositions (particularly soap bars or soap based liquid cleansers) usually contain 2,4,4′-trichloro-2′-hydroxydiphenyl ether (TRICLOSAN®) or trichlorocarbanilide (TCC) or p-chloro-m-xylenol as the active antibacterial agent. Usually the pH of such compositions is 9 to 10. While there are personal cleansing compositions (largely containing synthetic non-soap surfactants as explained earlier) which are neutral or low pH, however such compositions are generally not found to be effective against some bacteria particularly relevant for hand hygiene e.g., E. coli. 
WO10046238 A1 (Unilever) discloses cleansing compositions comprising thymol and terpineol in selective proportions to provide fast antimicrobial action.
WO11120780 A1 (Unilever) discloses super mild surfactant systems used in combination with skin or hair benefit agent(s). Disclosed surfactant systems have a combination of specific alkanoyls or mixtures of alkanoyl surfactants with specifically identified fatty acyl isethionate product to provide synergy which reduces irritation (as measured by Patch Testing).
WO9721795 A1 (Unilever) discloses cleaning composition of pH<6 or pH>8 which include ethoxylated nonionic surfactant of HLB of 10-14, a C1-C5 linear or branched alcohol. The use of 1 to 30 wt % of alcohol greatly improves the biocidal properties.
U.S. Pat. No. 6,146,622 A (Alcon Labs) discloses use of anionic amino acid based surfactants to enhance antimicrobial effectiveness in topically administrable pharmaceutical compositions containing at least one active ingredient.
Therefore, cleansing compositions which show antibacterial action but which at the same time are mild and gentle to the skin are generally difficult to formulate.
We have now been able to formulate highly alkaline, yet highly mild antibacterial cleansing compositions.
No attempt known to the applicant herein has ever been made to provide a composition having the stated seemingly opposite properties as it is inherently against the teachings of known art in view of the apprehended adverse impact on mildness. On the other hand, it is equally against the suggestions of known art to include an antibacterial agent in a mild and gentle personal cleansing composition because pH of such compositions is generally acidic.